$ D = \left[\begin{array}{rr}3 & 1 \\ 5 & 4\end{array}\right]$ What is $ D^{T}$ ?
Explanation: To find the transpose, swap the rows and columns. $ D^{T}$ = $\left[\begin{array}{rr}3 & 5 \\ 1 & 4\end{array}\right]$